Bin level control



May 15, 1945. ANDERSON 2,376,304

BIN LEVEL CONTROL Filed Aug. 7, 1943 3 Sheets-Sheet 1 uvvmrmx- J HELMER ANDERSON May 15, 1945. ANDERSON 2,376,304

BIN LEVEL CONTROL Filed Aug. 7, 1943 5 SheetsSheet 2- FIG.2

- /NVE/V7'0R.'- HELMER ANDERSON H. ANDERSON 2,376,304

BIN LEVEL CONTROL Filed Aug. 7, 1943 3 Shee'tsSheet 3 May 15, 1945.

IIII I/VVENTORJ- HELMER ANDERSON a o m Patented May 15, 1945 BIN LEVEL CONTROL ljelmer Anderson, Minneapolis, Minn assignor to General Mills, Inc., a corporation of Delaware Application August 'z, 1943. Serial No. 498.027

' '2 Claims. 01. 211-11) This invention relates to apparatus for auto-- matically controlling the flow of flour or the like to a bin by means of which the level of material in the bin may be maintained nearly constant while the materialis withdrawn from the bottom at regular or irregular intervals.

In a flour mill a single conveyor may carry hour to any one of a number of spouts, each leading to a flour bin which may be two, three or even four floors below the conveyor. Each of these spouts has a valve for controlling the flow of flour in that spout. Where the spout is very longand fills completely with flour, withdrawal of flour from the bin below will sometimes cause a vacuum to occur in the center of the spout due to the flour hanging up in the upper portion. This vacuum may even cause the spout to collapse.

An object of this invention is to provide a valve and means-for automatically operating it which will insure a feed of flour as needed to maintain a given level in the bin and one which will prevent flour from filling much of the spout, thereby precluding the possibility of the flour hanging up in the spout.

Another object is the provision of means for automatically maintaining a nearly constant depth, of flour in a bin so that the flour delivered to a hopper beneath from which bags are filled, will have a nearly uniform density. This is necessary for uniform weights in bags when filling and weighing are done automatically,

These and other objects, as will hereinafter appear, are described in the following specification and shown in the accompanying drawings in Figure 1 is a partial vertical section through a bin and the spout leading thereto, showing the valve closed and the mechanism for automatically controlling it;

Fig. 2 is a similar view-showing the valve open;

Fig. 3 is a perspective showing the valve and operating mechanism;

Fig. '4 is a partial longitudinal section on the line 4-4 of Fig. 3;

on the broken line several spouts and bins of which only one is shown.

A fiat-type valve I4 is located in the valve housing It forming part of the spout :and is secured on a squared shaft l8 which is suitably journaled in the sides of the housing [6 at one side of the spout proper and is located in a recess at one side so as to permit it to turn down out of the path of any flour which may be passing through the spout as shown in Fig. 2.

An operating lever 22 is secured to the shaft "and is yieldingly connected through a spring 24 with an operating lever 26 which is pivotally carried on a reduced and rounded portion of the shaft 18. A crank arm 23 is carried by the lever. 22 which is normally held in engagement with a stop 21 on the operating lever 26 by means of the tension spring 24. This operating arm is moved back and forth by means of a connecting rod 28 which is driven by a mechanism which will now be described.

A base 30 for the operating mechanism is carried on suitable joists or the like 32. To this are bolted support members 34, 3B in which are formed suitable bearings for a shaft 38 (Fig. 4). A flange 40 is secured on this shaft and has adjustably bolted thereon a crank arm 42 which carries a pin M to which is connected the outerend of the connecting rod 28.

y A ratchet wheel 50 is secured to a sleeve 52 which is rotatably mounted on the shaft 38, the

sleeve. carrying a sprocket 54 which is driven continuously by a chain by any suitable source of power, not shown.

The shaft 38 has firmly securedthereon a lever 56 which carries a stop 51 and a short transverse stud'58 which is suitably joumaled therein and which carries a pawl .68 which is adapted to engage any of the teeth 62 of the ratchet wheel 50. The pawl also carries a finger 64 and an arm 66, the latter being urged in a counterclockwise direction, as shown in Fig, 6, by means of a tension spring 68. The stop 51 limits the swing of the pawl 64. a

A detent 10 for the finger 64 at the top of its swing which is normally out of the path of the finger N, as shown in Fig. 1, is carried on a lever 12 ,which is pivotally mounted on a pin 14 which in turn is mounted on an extension support member 38 (Fig. 6). This support member also carries a solenoid which has a core 82 connected through links 84 to a lever arm 86 which is pivotally mounted at 88 on the support 35. One branch of this lever arm 80 connects through a link 92 with the lever 12 while another branch 8| serves as a detent for the finger dicator I is located near the top of the bin and has a suitable flexible diaphragm I02 of canvas and the like to which is secured a disk I04 which in turn carries a rod I06 which is pivotally con nected to a plate I08, the latter being pivotally mounted at IIII to a member II2 which serves also to support the periphery of the diaphragm I02. The plate I08 is provided with a weight III and carries a mercury switch H8 to the terminals of which are secured electric leads I20 and I22. These are secured through leads I24, I28 to the terminals of the solenoid 80 to a suitable source of electric current I28 which may be either direct or alternating.

From the foregoing it will be seen that with the bin I0 filled, as shown in Fig. l, the diaphragm I02 is pressed outwardly by the hour thereby opening the mercury switch H8, de-energizing the solenoid 80, and enabling the spring 94 to raise the detent 9! in the path of the finger 04, at the same time raising the detent I0 so a to release the finger 64 from the position in which we find it in Fig. 2. Upon release of the finger 84 by the pawl I0 the spring 88 causes the pawl 80 to rotate in a. counter-clockwise direction about the stud 58 so asto bring it into engagement with one of the teeth of the ratchet wheel 50 which is continuously rotating and which carries the arm 58 around with it until the finger B4 strikes the detent 9| (Fig. 1). During this time the valve I4, which was held open as shown in Fig. 2 so long as the finger 64 was held by the detent I0, is now moved to closed position as shown in Fig. 1.

To assist in disengaging the pawl 00 from the I teeth of the ratchet wheel, I have provided a cam I30 which is adjustably secured by means of bolts I32 to a flange I34 which is keyed on the shaft 38. This cam, which can-be seen most clearly in Fig. 5, has two arcuate portions terminating in'abrupt shoulders I38, either of which may be engaged by a cam follower roller I38 rotatably mounted on a pin I40 carried by a lever arm 2 which is drawn by a spring I so that the roller III is urged against the face of the cam I30.

Thus it will be seen that by properly adJusting the cam I39, it will urge the finger 04 forwardly into either of thedetents I0 or 8| at the instant thisiinger strikes either of the detents, thereby causing the pawl to become disengaged from the teeth of the sprocket wheel.

.While I have shown and described but a single embodiment of my invention, it is to be understood that it is capable of many modifications. Changes, therefore, may be made which do not depart from the spirit and scope of my invention as disclosed in the appended claims.

I claim as my invention: 1. In combination, a bin. a spout leading to the bin, a valve in the spout for controlling the flow of granular material through the spout, means operable by material in the bin for closing the valve when the material in the bin reaches a predetermined level, and means operable for opening the valve when the level or material in the bin reaches a lower predetermined level, said means including spring means whereby the valve is yieldable on opening when the space in the spoiut below the valve is filled with granular maer al.

2. In combination, a bin, a -spout leading to the bin, a valve in the spout for controlling the flow of granular material through the spout, a lever operably connected to the valve for opening and closing the same, a constantly revolving ratchet wheel, an arm operably connected to the lever and rotatable about the axis of the ratchet wheel, a spring-pressed pawl carried by the arm and adapted to be forced by the spring into engagement with the ratchet wheel, a finger carried by the pawl, .detents for stopping the linger in positions about one-half revolution apart corresponding to open and closed positions of the valve, means for moving the pawl forward more rapidly than the ratchet wheel as the finger engages the detent to cause the pawl to release, and means operable by the level of material in the bin for moving said detents into the path oi said finger.

HELMER ANDERSON. 

